| 摘要 |
<p>PURPOSE: To optimize both reading and programming characteristics by operating an array source driving circuit and a bit line driving circuit in accordance with reading/programming and selectively switching the connection of the first and the second terminals of EP-ROM. CONSTITUTION: For reading out, the terminal 140 of P-ROM 152 selected from EP-ROMs 30-70 is connected to ground with FET 142 turned on by an array source driving circuit 74; and also, a terminal 154 is connected to a read sense node 115 through transistors 156, 116 by bit line driving circuits 94-100, 120. For programming, the terminal 140 is connected to Vbias with FET 138 turned on, and the terminal 154 to ground. As a result, a memory cell can be read out from one side and programmed from the other side; therefore, it is possible to make a graded junction for the read side and a rapid change junction for the program side. Thus, the optimum operation can be carried out for both reading and programming.</p> |
